- An archlike anatomical structure or fold, such as the arched band of white matter beneath the corpus callosum of the brain.
- In <em>topical geom.</em>, a part of a surface which, in conjunction with another similar part which inseparably accompanies it, increases the cyclosis of the surface by two.
- In <em>anat.:</em> A median symmetrical arched formation in the brain, beneath the corpus callosum and septum lucidum, vaulting over the optic thalami and the third ventricle, and running into the floor of each lateral ventricle.
- Some other arched, vaulted, or fornicated formation: as, the <em>fornix conjunctivœ</em>, the vault of the conjunctiva.
- In <em>conch.:</em> The vaulted or excavated part of a shell under the umbo.
- The more concavo-convex one of the shells of an inequivulve bivalve, as an oyster.
- In <em>botany</em>, a small arching crest or appendage in the throat or tube of a corolla.
- An arch or fold
- Esp., two longitudinal bands of white nervous tissue beneath the lateral ventricles of the brain.
- An <xref>archlike</xref> structure or fold.
- Specifically, the arched bundle of fibres or <xref>axons</xref> at the base of the <xref>brain</xref>.
- generally any arch shaped structure (but often it refers to the arched roof of an anatomical space)
- an arched bundle of white fibers at the base of the brain by which the hippocampus of each hemisphere projects to the contralateral hippocampus and to the thalamus and mamillary bodies